How to use

reverseOrder

method

in

com.twelvemonkeys.util.CollectionUtil

@Test(expected = IllegalArgumentException.class)
public void testReverseOrderNull() {
  CollectionUtil.reverseOrder(null);
}

@Test
public void testReverseOrder() {
  Comparator<String> naturalOrder = new NaturalOrder<String>();
  Comparator<String> reverse = CollectionUtil.reverseOrder(naturalOrder);
  assertNotNull(reverse);
  assertEquals(0, naturalOrder.compare("foo", "foo"));
  assertEquals(0, reverse.compare("foo", "foo"));
  assertTrue(naturalOrder.compare("bar", "baz") < 0);
  assertTrue(reverse.compare("bar", "baz") > 0);
  assertTrue(naturalOrder.compare("baz", "bar") > 0);
  assertTrue(reverse.compare("baz", "bar") < 0);
}

@Test
public void testReverseOrderRandomIntegers() {
  Comparator<Integer> naturalOrder = new NaturalOrder<Integer>();
  Comparator<Integer> reverse = CollectionUtil.reverseOrder(naturalOrder);
  Random random = new Random(243249878l); // Stable "random" sequence
  for (int i = 0; i < 65536; i++) {
    // Verified to be ~ 50/50 lt/gt
    int integer = random.nextInt();
    int integerToo = random.nextInt();
    assertEquals(0, reverse.compare(integer, integer));
    assertEquals(0, reverse.compare(integerToo, integerToo));
    int natural = naturalOrder.compare(integer, integerToo);
    if (natural == 0) {
      // Actually never hits, but eq case is tested above
      assertEquals(0, reverse.compare(integer, integerToo));
    }
    else if (natural < 0) {
      assertTrue(reverse.compare(integer, integerToo) > 0);
    }
    else {
      assertTrue(reverse.compare(integer, integerToo) < 0);
    }
  }
}

@Test(expected = IllegalArgumentException.class)
public void testReverseOrderNull() {
  CollectionUtil.reverseOrder(null);
}

@Test(expected = IllegalArgumentException.class)
public void testReverseOrderNull() {
  CollectionUtil.reverseOrder(null);
}

@Test
public void testReverseOrder() {
  Comparator<String> naturalOrder = new NaturalOrder<String>();
  Comparator<String> reverse = CollectionUtil.reverseOrder(naturalOrder);
  assertNotNull(reverse);
  assertEquals(0, naturalOrder.compare("foo", "foo"));
  assertEquals(0, reverse.compare("foo", "foo"));
  assertTrue(naturalOrder.compare("bar", "baz") < 0);
  assertTrue(reverse.compare("bar", "baz") > 0);
  assertTrue(naturalOrder.compare("baz", "bar") > 0);
  assertTrue(reverse.compare("baz", "bar") < 0);
}

@Test
public void testReverseOrderRandomIntegers() {
  Comparator<Integer> naturalOrder = new NaturalOrder<Integer>();
  Comparator<Integer> reverse = CollectionUtil.reverseOrder(naturalOrder);
  Random random = new Random(243249878l); // Stable "random" sequence
  for (int i = 0; i < 65536; i++) {
    // Verified to be ~ 50/50 lt/gt
    int integer = random.nextInt();
    int integerToo = random.nextInt();
    assertEquals(0, reverse.compare(integer, integer));
    assertEquals(0, reverse.compare(integerToo, integerToo));
    int natural = naturalOrder.compare(integer, integerToo);
    if (natural == 0) {
      // Actually never hits, but eq case is tested above
      assertEquals(0, reverse.compare(integer, integerToo));
    }
    else if (natural < 0) {
      assertTrue(reverse.compare(integer, integerToo) > 0);
    }
    else {
      assertTrue(reverse.compare(integer, integerToo) < 0);
    }
  }
}

@Test
public void testReverseOrder() {
  Comparator<String> naturalOrder = new NaturalOrder<String>();
  Comparator<String> reverse = CollectionUtil.reverseOrder(naturalOrder);
  assertNotNull(reverse);
  assertEquals(0, naturalOrder.compare("foo", "foo"));
  assertEquals(0, reverse.compare("foo", "foo"));
  assertTrue(naturalOrder.compare("bar", "baz") < 0);
  assertTrue(reverse.compare("bar", "baz") > 0);
  assertTrue(naturalOrder.compare("baz", "bar") > 0);
  assertTrue(reverse.compare("baz", "bar") < 0);
}

@Test
public void testReverseOrderRandomIntegers() {
  Comparator<Integer> naturalOrder = new NaturalOrder<Integer>();
  Comparator<Integer> reverse = CollectionUtil.reverseOrder(naturalOrder);
  Random random = new Random(243249878l); // Stable "random" sequence
  for (int i = 0; i < 65536; i++) {
    // Verified to be ~ 50/50 lt/gt
    int integer = random.nextInt();
    int integerToo = random.nextInt();
    assertEquals(0, reverse.compare(integer, integer));
    assertEquals(0, reverse.compare(integerToo, integerToo));
    int natural = naturalOrder.compare(integer, integerToo);
    if (natural == 0) {
      // Actually never hits, but eq case is tested above
      assertEquals(0, reverse.compare(integer, integerToo));
    }
    else if (natural < 0) {
      assertTrue(reverse.compare(integer, integerToo) > 0);
    }
    else {
      assertTrue(reverse.compare(integer, integerToo) < 0);
    }
  }
}